He probably grew a bit more that year(2000-2001), which is why at his current physical state, he's able to cover the court much better than when he first started.
Yeah, he looks noticeable shorter there than in 2001. Maybe 5"10 or so?
Yeah, back then, his mentality was either hitting flat down-the-middle shots or sharply angled "wiper" shots. Pretty dang impressive even then the angles he could make up and the raw power of his normal game, and in that sense, he actually played like how Gasquet still does.
He wasn't particulary quick around the court.
His footwork wasn't great. He didn't stay low to the ground. Most of his shots were created from the whippy action on his FH. Though it's always interesting how much he went to the net, how much then he truly believed in a true attacking, all-court style.
That's my favorite thing to point out about Federer. The dude
worked at his footwork, movement, court anticipation, and point construction -- all which flow into each other -- until he was among the very best movers in the game. You can even fast-forward to 2003, and still see that his positioning was not as low to the ground and precise as it was in his 3-year domination span.